UC Riverside

Ecosystems are undergoing unprecedented rates of change with severe consequences for biodiversity loss, yet natural resilience and restoration of ecosystems provides hope to mitigate these losses. Despite the potential for natural recovery, there are thresholds and feedback mechanisms that inhibit recovery that are often driven by invasive species. Consequently, understanding how invasive species interact with their surrounding communities and how they respond to restoration efforts is crucial information for effective management and successful restoration. My dissertation seeks to understand how the impact of invasive plants prevents effective restoration through a combination of field experiments with paired greenhouse components to capture robust processes in the field and disentangle the underlying mechanisms in a controlled greenhouse setting. My first two chapters investigate how a local and regionally obnoxious novel invasive forb, Oncosiphon pilulifer, responds to the common management technique of prescribed fire, and how Oncosiphon interacts with soil biota to inhibit native plant growth. My final chapter focuses on how the multiple factors of seed limitation, invasive litter accumulation, and soil symbiont depletion constrain restoration success in a Northern Californian annual grassland. Taken together, my dissertation projects aim to both address fundamental questions in community ecology and produce actionable science for land management practitioners.